Yarn delivery mechanism

ABSTRACT

APPARATUS FOR DELIVERY OF YARN TO TEXTILE TREATING MACHINES COMPRISING MEANS FOR BRINGING INTERACTING ROLLER TOGETHER AT EQUAL SURFACE SPEEDS, MAINTAINING SAME TOGETHER AT CONSTANT PRESENT PRESSURE, AND ALLOWING SEPARATION OF SAME IN THE EVENT OF SERIOUS IRREGULARITIES IN YARN DELIVERY.

United States Patent Inventor llelmut Ritter [50] Field of Search226/35, 90, Canton St.Gall, Switzerland 154, 155,176, 177, 181, 186,187, 169

Appl. NO. 745,017

Filed July 15, 1968 [56] References Cited Patented June 28, 1971 UNlTEDSTATES PATENTS Assisnee Hrberleiu Patent Corporation 3,088,642 5/1963Kingsley 226/176(X) New York, 3,116,531 1/1964 111115 226/176-(X)Priority s- 28, 1967 3,176,895 4/1965 Kurth 226/176 i gz g PrimaryExaminer- Richard A. Schacher Attorney-Ward, Haselton, McElhannon,Brooks and Fitzpatrick YARN DELIVERY MECHANISM ABSTRACT: Apparatus fordelivery of yarn to textile treating 9 claimsflnmwing Figs machinescomprising means for bringing interacting rollers US. Cl 226/90,together at equal surface speeds, maintaining same together at 226/155,226/ 169, 226/ 187 constant preset pressure, and allowing separation ofsame in Int. Cl G03b 1/56 the event of serious irregularities in yarndelivery.

20 Z4 Z 11 H I i 1 j PATENTEU JUN28 l97l SHEET 1 BF 2 l N VEN TOR.

f/Emur w/mgm/www iigg 1 YARN nsuvsav MECHANISM This invention relates toapparatus useful in the feed or delivery of lengths of yarn from onelocation to another, and more particularly with the delivery ofindividual or ply-twisted yarns or threads such as false twist yarnslongitudinally into textile machines operating at high speeds.

It is known in the textile machine art to deliver individual orply-twisted yarns or threads by means of individual rollers, belts orpairs of rollers, wherein the delivery means for all stations on amultistation machine may be driven by a common drive shaft. In caseswherein the delivery means comprise fixed drive rollers and idlerdelivery rollers engaging the surface of the drive rollers and betweenwhich the yarns pass, it is necessary when exchanging a supply bobbin,or when a yarn breakage has occurred, to separate the particular driveand delivery'roller means at the appropriate'station, and in accordancewith known constructions, since all drive roller means are commonlydriven and all deliveryroller means are commonly mounted, as where eachsuch roller means is a single elongate roller, the entire system istemporarily immobilized during rethreading. Then too, upon completion ofrethreading, the delivery and drive means are brought back into surfacecontact while the drive means continues to rotate at its normal speed.The yarns, positioned between the drive and delivery rollers, are thusexposed to sudden high frictional forces which may cause breakage orstructural changes to occur.

At yarn speeds of the order of 100 to 120 meters per minute, which isnot unusual in false twist machines, for example, the machine maybethreaded by winding the yarn around a takeup bobbin which is driven byhand or mechanically, whereupon the bobbin pulls the yarn through themachine until the delivery system is reactivated. Such hand operation,however, is not feasible in modern machines having delivery speeds of upto 500 m/min. and more, since although the yarns are drawn through themachine by means ofa winding bobbin, the friction forces to which theyarns are subjected between the drive and delivery rollers when the sameare pressed into contact are too high and often cause deformation andbreakage.

A further problem arises from the fact that it is desirable to maintainthe delivery roller in contact with the driving roller under a constantpressure.

Additionally, for yarn speeds of the order of 500 m/min, known systemsare inadequate since they do not absorb the centrifugal forces of thedelivery roller means due to the high speeds of rotation thereof whichalso cause pressure variations on the drive roller. This leads tovibration, noise and yarn deformation and damage.

Accordingly, I have conceived a yarn delivery mechanism whicheffectively overcomes the foregoing difficulties and disadvantages.Thus, I contribute by my invention apparatus employing interacting driveand delivery rollers for the delivery of yarns and the like in textilemachines such as false twist machines, for example, according to which Iam able to bring the interacting rollers to substantially the samesurface speeds before their respective interacting surfaces come intocontact with the yarn running between them while avoiding theundesirable vibration already referred to, and without damage to thethread.

Essentially, my invention comprises apparatus for the delivery of yarnsand the like in textile machines comprising, a rotatable driving roller,a delivery roller mounted for idling rotation, the rollers havingopposed interacting delivery surfaces, means for rocking the deliveryroller to bring the interacting surfaces into and out of contact, meansinteracting with the delivery roller as the latter is shifted towardsthedriving roller to bring the surface of the delivery roller tosubstantially the speed of rotation of the surface of the driving rolleras contact between the surfaces is effected. The last-men tioned meansmay preferably take the form ofan annular projection extending radiallyoutwardly of an edge of the driving roller and formed with a surfacearranged to engage an edge of the delivery roller as the surface of thedelivery roller moves towards that of the driving roller. This initialcontact starts rotation of the delivery roller and brings it up to thedesired speed as it advances towards the surface of the driving roller.Thus, a spring arrangement preferably carried at the end of eachdelivery roller axle is utilized to provide the axial force urging theedge of that roller towards the annular projection on its interactingdriving roller. Thus, it will be seen that as the delivery roller isshifted towards the driving roller, its edge first engages theprojection formed on the driving roller and the delivery roller beginsto rotate although the opposed interacting surfaces of the two rollershave not yet made contact. The delivery roller gradually assumes thespeed of the driving roller due to the preliminary contact with theprojection, which contact is assured by the spring arrangement urgingthe delivery roller axially towards the projection. The projection ispreferably located at one edge of the particular driving roller and isformed with a flank inclined towards that roller. Finally, when the twointeracting surfaces of the respective rollers are brought into contactwith the yarn between the interacting surfaces these surfaces will berotating at substantially the same surface speeds.

To ensure proper contact between the delivery roller and the projection,I provide means for urging the delivery roller axially towards theprojection.

In order to effect rocking movement of the delivery roller, 1 find itconvenient to mount same eccentrically on an axis parallel to that ofthe driving roller, and I provide a manually engageable arm or lever foreffecting the rocking action.

It will be understood that while each driving roller may be fixedlymounted on a single-drive shaft for rotation therewith, each of thedelivery rollers is individually mounted so that a yarn may be threadedwithout interrupting the delivery of yarn for treatment at otherstations of the machine.

A further aspect of the invention resides in the provision of a hubconcentric with the delivery roller but eccentric about its axis andupon which the delivery roller is mounted for idling rotation. The hubis mounted on the delivery roller axle and this arrangement permits thedelivery roller readily to be brought into and out of contact with thedriving roller merely by rotation of the hub. For this purpose, amanually engageable radially extending arm is fixed to the hub to rocksame to the position desired, and a stop in the form of a pin may beprovided on the axle to limit movement of the hub in either direction ofrotation when the delivery roller and the driving roller are broughtinto or out of contact.

As has already been mentioned, it is desirableto maintain the deliveryroller in contact with the driving roller under a constant pressure. Ifa different pressure should be required to correspond to different yarncharacteristics, the pressure spring necessary for exerting the contactpressure can be changed. The sole purpose of this spring is to presetthe mechanism at the required contact pressure, it exerts only the forcecorresponding to its size and is inactive when the machine is inoperation. ln addition, it is desirable to incorporate in the deliverymechanism a safety device which enables the delivery roller to be liftedfrom the driving roller when interruptions in operation occur.

To this end, I provide a mounting construction for the delivery rollerwhereby it can not only be swiveled as described, but is pressed againstthe driving roller with a specific force when the two are in contact.This force is determined by a pressure spring fitted in the mountingduring installation of the delivery mechanism on any suitable machine,but is then locked by screws with the result that the spring is madeinactive but the contact pressure is maintained. Whenever it is swiveledinto the operating position the delivery roller, which is fitted with aresilient cover, is pressed against the driving roller at the originallyset contact pressure. The mounting also incorporates means for raisingthe delivery roller from the driving roller only when a specificpressure limit is exceeded. The pressure limit can, if required, bealtered by exchanging the spring which exerts this pressure and which isalso fitted in the housing. This pressure limit should be at such alevel that the delivery roller is not raised from the driving roller asa result of the passage of normal yarn slubs or slubs caused by twoknotted yarn ends, as this would be contradictory to the very purpose ofthe invention. The sudden increase in yarn volume is absorbed by theresilient cover of the delivery roller. The pressure limit is exceededand the delivery roller raised from the driving roller when, e.g., as aresult of a thread break, the yarn becomes entangled round one of theserollers.

Further specific features and advantages of the invention will behereinafter more fully set forth with reference to the annexed drawings,showing a presently preferred embodiment of the invention and certainmodifications thereof, in which:

FIG. I is a side elevational view of apparatus in accordance with myinvention;

FIG. 2 is a front elevational view, partly in section, of the apparatusof FIG. 1;

FIG. 3 is a top plan view of the apparatus of FIGS. 1 and 2; and

FIG. 4 is a cross-sectional view taken along the lines 44 of FIG. 3.

Referring now to the drawings, and more particularly to FIGS. 1, 2 and3, there is shown a support beam extending parallel to a shaft 11 whichrotates continuously during operation of the machine and on which aremounted several driving rollers 12 for rotation therewith. These drivingrollers are spaced along the shaft 11 at the several delivery stations,but as they are identical in configuration only one such roller isshown. The roller 12 may be conveniently fixed on the shaft 11 by meansof a half worm gear 14 and taperlock mounting 15 secured in place byscrews 16. A chrome plated steel ring 17 is press fit on the peripheralsurface 19 of the roller.

The driving roller 12 is formed with a radially outwardly extendingprotrusion or flange 20 at one edge thereof, the inner face (FIG. 2) ofwhich tapers in a gentle arc downwardly towards the surface of theroller for a purpose to be later described.

Referring to FIGS. 1 and 3, it will be seen that a mounting bracket 21is secured to the beam 10 by means of screws 22, and that the bracket isformed with a generally cylindrical housing 24. A shaft 25 about whichmore will later be said extends out of the upper part of the housing 24and is rigidly connected to an L-shaped support 26 by means ofa washer27 and nut 29. Y

A pin 30 (FIG. 2) extends downwardly from the end ofa leg 26' of thesupport 26 and passes between two fingers 31 (FIGS. 2 and 4) extendingoutwardly of the upper end of the housing 24. Another leg 26" of thesupport 26 is formed with a bore 32 (FIG. 2) into which is press fit anextension 34 of a shaft 35 axially parallel to the shaft 11.

The shaft 35 supports an eccentrically formed hub 36 which is rotatableand axially shiftable relatively to the shaft and to which is secured amanually engageable arm or lever 37. The hub 36 is fonned with adownwardly facing sector-shaped groove 39 which serves as a limit stopby reason ofits relationship to a pin 40 fixed to the shaft 35 andextending into the groove.

A ball bearing 41 is fixedly mounted on a portion of the hub 36 ofreduced diameter and is secured in place by a shoulder formed on the hubby the reduction and by an external circlip 42 and a pair of cup springs44, acting against each other as shown in FIG. 2. The ball bearing 41supports a delivery roller 45 for rotation about the shaft 35. Theroller 45 may be formed of a metal ring 46 covered by a ring 47 ofsuitable resilient plastic.

At the right end of the shaft 35, as viewed in FIG. 2, a cup 49 ismounted by means of a fixing screw 50 passing through the center of thecup and threaded into the end of the shaft 35. A spring 51 bears againstthe interior of the cup 49 and against a cup 70 which in turn bearsagainst one end of the hub 36 so that the latter and with it thedelivery roller 45, are urged axially along the shaft 35 to the leftunder spring force.

From the description thus far, it will be seen that, in the event of ayarn breakage or other need to rethread a particular station of yarntreating machine, the lever 37 is manually shifted whereupon the hub 36rotates relatively to the shaft 35; and because of its eccentricconstruction, lifts the delivery roller 45 away from the driving roller12 so that rethreading can be effected. It will be understood that uponseparation of the opposed interacting delivery surfaces of the tworollers, the driving roller continues to rotate and other machinestations continue to operate.

When it is desired to return the delivery roller into contact with thedriving roller, the lever 37 is shifted in the appropriate direction sothat the eccentricity of the hub 35 causes the surface of roller 45 toadvance towards that of roller 12. Upon shifting of the delivery roller,the pin 40 rocking in the segmental groove 39 serves a limit control.

As the delivery roller 45 approaches the driving roller 12, it

will be seen that under the urging of spring 51, the left edge of thedriving roller first engages the inner face of the rotating projectionor flange 20 formed on the driving roller 12. This initial contactstarts the delivery roller rotating and, as it approaches the drivingroller, brings its delivery surface up to substantially the speed of theinteracting delivery surface of the driving roller, so that as contactis made between the surfaces, the frictional forces on the yarntherebetween are kept to a minimum.

Turning now to FIGS. 2-4, it will be seen that the housing 24, which hasalready been referred to, receives the shaft 25, the lower end of whichis provided with a nut 52 and washer 54 which abuts a disc 55 moveablelongitudinally in the hous- Within the housing 24, a spring block 56 isformed with an axial bore 57 and an opposed wider bore 59 forming a wall60 therebetween which is centrally apertured for passage therethrough ofthe shaft 25. The shaft 25 is stepped to form an annular shoulder 61which bears against the wall 60. An end plate 62 is fixed in the top endof the housing 24 by means of an internal circlip 64 and a protectioncap 65 is removably positioned in the other end of the housing. A spring66 extends between the end plate 62 and the wall 60 to urge the block 56towards the bottom of the housing 24.

It will be noted that the block 56 is concentric with the axis of thehousing 24 and a pair of setscrews 67 enables the block 56 to be lockedagainst movement when it is located in the desired longitudinal positionin the housing 24, which is the case when the delivery roller is incontact with the driving roller. In this position the spring 66 exertsthe pressure required for the delivery roller. This pressure, as alreadydescribed in more detail, is locked by means of screws 67. The wholeoperation is made possible by the fact that a spring 69, which serves tofix a safety pressure limit, bears against the disc 55 and the bottom ofthe wall 60 with a force several times as great as that of the spring66. As a result of this construction, the compressive force of spring69, the shaft 25, together with the nut 52, the washer 54, the disc 55,the block 56 and the spring 69 are to be regarded as a compact unit. Theshaft 25 carries the support 26, and this in turn the shaft 35 and thedelivery roller 45, so that, if the delivery roller is separated fromthe driving roller by an abnormal force, i.e., the compressive force(safety pressure limit) of spring 69 is exceeded, the shaft 25, togetherwith the nut 52, the washer 54 and the disc 55, shifts upwards,compressing the spring 69 tightly together.

The pin 30 already referred to as passing between the fingers 31 formedon the housing 24 prevents rotation of the support 26, and therefore theshaft 35 and the delivery roller 45, from becoming misaligned relativelyto the driving roller 12.

From the foregoing description it will be understood that I havecontributed yarn delivery apparatus of the class described usinginteracting rollers which can be separated and brought together atsubstantially identical surface speeds and which permits the rollers tobear against each other under a preset but not adjustable pressure. Inaddition, the apparatus revents a separation of the two rollers whenyarn slubs pass between them, as this would be an unnecessaryinterruption in smooth yarn delivery. The passage of yarn slubs causesthe preset contact pressure, but not the safety pressure limit, to beexceeded, and consequently the delivery roller maintains its position.The sudden increases in yarn volume produced by the slubs are absorbedby the resilient cover of the delivery roller. At the same time, myconstruction allows the delivery roller to move away from the drivingroller in the event that the safety pressure afforded by spring 69 inthe housing 24 is exceeded by serious irregularities in the yarndelivery such as by the formation of a pad of thread on one of therollers, for example. The foregoing advantages are achieved in a mannerto materially reduce the possibility of breakage and damage to the yarn,to deliver yarn more smoothly and to protect the delivery mechanism by asafety device.

I believe that the construction and operation of my novel yarn deliveryapparatus will now be understood, and that the advantages of myinvention will be fully appreciated by those persons skilled in the art.

Iclaim:

1. ln apparatus for delivering yarns and the like in textile machines, arotatable driving roller, a delivery roller mounted for idling rotation,the rollers having opposed interacting delivery surfaces, means forrocking said delivery roller to bring said interacting surfaces into andout of contact, means interacting with said delivery roller as thelatter is shifted towards said driving roller to bring the surface ofsaid delivery roller to substantially the speed of rotation of thesurface of said driving roller as contact between said surfaces iseffected said last mentioned means comprising an annular projectionextending radially outwardly of an edge of said driving roller andformed with a surface arranged to engage an edge of said delivery rolleras the surface of said delivery roller moves towards that of saiddriving roller.

2. ln apparatus for delivering yarns and the like in textile machines,according to claim 1 and further including means for rocking saiddelivery roller to bring said interacting surfaces into and out ofcontact, and pressure setting means effective when said surfaces are incontact to maintain a constant contact pressure therebetween.

3. Apparatus according to claim 2, wherein said last-mentioned meanscomprises a spring pressing said delivery roller against said drivingroller and locking means effective to maintain said spring forceconstant.

.4. Apparatusaccording to claim 3, wherein said spring force is presetso that said delivery roller is pressed against said driving rollerunder a specific force.

5. ln apparatus for delivering yarns and the like in textile machines,according to claim 1 and further including means for rocking saiddelivery roller to bring said interacting surfaces into and out ofcontact, pressure setting means effective when said surfacesare incontact to maintain a constant contact pressure therebetween and safetypressure control means including a spring permitting movement ofsaiddelivery roller in a direction away from said driving roller whenserious irregularities in yarn delivery occur.

6. ln apparatus for delivering yarns and the like in textile machines, arotatable drive shaft, a driving roller mounted for rotation with saiddrive shaft, a delivery roller mounted for idling rotation, said rollershaving .opposed interacting delivery surfaces, means for rocking saiddelivery roller to bring said interacting surfaces into and out ofcontact, said driving roller having an annular projection adjacent itsinteracting surface, and means urging said delivery roller axially tocause its edge to engage a surface of said projection prior to effectingcontact of said delivery surfaces when said delivery roller is movedtowards said driving roller thus to bring the interacting surface ofsaid delivery roller to substantially the speed of rotation of saiddriving roller before the interacting surface of said contact betweensaid delivery surfaces is effected.

7. Apparatus according to claim 6, wherein said projection is formed atan end of said driving roller with a surface sloping towards theinteracting surface of same.

8. Apparatus according to claim 6, wherein said means for rocking saiddelivery roller includes an eccentrically shaped hub boredconcentrically with the delivery roller and a manually engageable armextending from said hub by which said hub may be rotated to bring thesaid rollers into and out of contact.

9. Apparatus according to claim 8, wherein means are provided to limitrotation of said hub in either direction when said rollers are broughtinto or out of contact.

